Identifying Unknown Fluorine-Containing Compounds in Environmental Samples Using F NMR and Spectral Database Matching.

The ubiquity of per- and polyfluorinated alkyl substances (PFAS) in the environment is a continuing concern. While typical analytical methods for the analysis of PFAS include both targeted and non-targeted mass spectrometry, there remains a significant portion of fluorinated compounds that are not accounted for by these routine methods. It has been previously demonstrated that F NMR can be used to identify these compounds, helping to close the mass balance on total fluorine in the environment.

A field-validated equilibrium passive sampler for the monitoring of per- and polyfluoroalkyl substances (PFAS) in sediment pore water and surface water.

A simple equilibrium passive sampler, consisting of water in an inert container capped with a rate-limiting barrier, for the monitoring of per- and polyfluoroalkyl substances (PFAS) in sediment pore water and surface water was developed and tested through a series of laboratory and field experiments. The objectives of the laboratory experiments were to determine (1) the membrane type that could serve as the sampler's rate-limiting barrier, (2) the mass transfer coefficient of environmentally relevant PFAS through the selected membrane, and (3) the performance reference compounds (PRCs) that could be used to infer the kinetics of PFAS diffusing into the sampler. Of the membranes tested, the polycarbonate (PC) membrane was deemed the most suitable rate-limiting barrier, given that it did not appreciably adsorb the studied PFAS (which have ≤8 carbons), and that the migration of these compounds through this membrane could be described by Fick's law of diffusion.

Noise-Reduced Quantitative Fluorine NMR Spectroscopy Reveals the Presence of Additional Per- and Polyfluorinated Alkyl Substances in Environmental and Biological Samples When Compared with Routine Mass Spectrometry Methods.

Per- and polyfluorinated alkyl substances (PFAS) are ubiquitous throughout the environment. Analysis of PFAS is commonly performed using both targeted and nontargeted mass spectrometry methods. However, it has been demonstrated that measurements of fluorinated compounds in the environment by mass spectrometry often fall short of the total fluorine concentration.

The Sulfoximine Insecticide Sulfoxaflor and Its Photodegradate Demonstrate Acute Toxicity to the Nontarget Invertebrate Species Daphnia magna.

The environmental fate and persistence of sulfoxaflor is of significant interest given the potential for the insecticide to impact nontarget organisms, particularly pollinating and aquatic species. In the present study we examine the potential for sulfoxaflor, a new sulfoximine insecticide, to undergo degradation and transformation in sediments and the aquatic environment. Following application of the active substance as a foliar spray or seed coating, sulfoxaflor can be found in the soil at a mass percentage of up to 61% of the total applied concentration.

The Environmental Degradation and Distribution of Saflufenacil, a Fluorinated Protoporphyrinogen IX Oxidase-Inhibiting Herbicide, on a Canadian Winter Wheat Field.

Saflufenacil when applied to a field is susceptible to transport, degradation, and transformation. We used a laboratory-based approach to model the fate of saflufenacil in the environment, the results of which are compared directly with those observed in a field study where saflufenacil was applied to a crop of winter wheat at a standard rate of 63 g of active ingredient/hectare. The water solubility of 2.